3D打印的发展带来回收标准的变革

The 3-D printing revolution has changed the way we think about plastics. Everything from children's toys to office supplies to high-value laboratory equipment can be printed. The potential savings of producing goods at the household- and lab-scale is remarkable, especially when producers use old prints and recycle them. Buying plastic filament for printing can be expensive, says Joshua Pearce, the lead researcher in the Open Sustainability Technology group at Michigan Technological University. Pearce and his students have whittled the cost of printing to ten cents per kilogram -- down from $30 per kilogram.

They made this leap by recycling plastic that had already been printed, using a recyclebot and plastic resin codes developed by the team.

In a new paper from the research group, published in Resources, Conservation and Recycling, the authors lay out how they achieved this price reduction and how to recycle 3-D printed objects more broadly.

"The centralized paradigm of both manufacturing and recycling is being challenged by the rise of 3D printing," Pearce says, explaining that labeling and reusing materials is voluntary.

Current labeling schemes, however, are not detailed enough for 3-D printed recycling. Plastic is not just plastic; there are many kinds, and specific polymers behave in specific ways -- which makes a big difference for 3-D printing.

"We want to know about polymers the same way a chemist would," Pearce says, admitting that the seven codes in the US recycling system fall short. In comparison, China has 140 codes for different polymers. "Currently, the most common 3-D printed plastics are grouped in the category seven polymers in the US," he adds.